1. Field of the Invention
The present invention relates to a head driving device, an inkjet printer comprising the same, and a data processing method thereof. More particularly, the present invention relates to a head driving device, an inkjet printer comprising the same, and a data processing method thereof, which is capable of reducing electromagnetic interference (EMI) and processing data at a high speed when printing data are transmitted via an internal data bus.
2. Description of the Related Art
In general, a printer is a means for printing information processed by external equipment, such as a computer, on a record medium and may include a wired dot method, a thermal transfer method and an inkjet method according to a print method of a print head.
The print head of the inkjet printer has a plurality of nozzles for jetting ink to form images on a record paper according to a print instruction. In a printing mechanism of the inkjet printer, the print head is a print device for embodying a requested printing operation and is driven by a head driving device to perform the printing operation by jetting a proper amount of print ink on the record paper.
FIG. 1 is a control block diagram illustrating a head driving device of a conventional inkjet printer.
As shown in FIG. 1, the head driving device of the conventional inkjet printer includes a shift register 1 for storing serial printing data output from a head controller of the inkjet printer according to a serial clock synchronization signal, a latch 2 for latching the printing data input to the shift register 1 according to a load signal, a gate array 3 for performing an AND operation between a latched signal and a jet pulse, and a field effect transistor (FET) array 4 being turned on/off according to an output signal of the gate array 3 and applying a voltage of Vph to thermal elements of the nozzles, thereby discharging ink of a relevant nozzle.
Here, for the purpose of convenience of explanation, assuming that the number of an address group is one and data are composed of 10 bits, a total number of nozzles through which ink can be discharged at a time is 10, which is a product of the data and the address.
As shown in FIG. 1, the data are latched according to the load signal. Such a latch operation is performed in a similar manner in an address group for each nozzle. In addition, the latched data are output to the FET array 4, which is a final stage for ink discharge, together with the jet pulse, via the gate array 3.
As mentioned above, the head driving device receives the serial printing data from the head controller and outputs the data of 10 bits corresponding to one address to the FET array 4 at a time. As a result, since data buses in the head driving device are elongated in one way, a problem may arise in which deterioration of an EMI characteristic occurs between signals.
Accordingly, there is a need for an improved head driving device in an inkjet printer and a data processing method that improves an EMI characteristic between signals.